1. Field of the Invention
The present invention relates to a portable X-ray imaging apparatus.
2. Description of the Related Art
In recent years, an apparatus that acquires digital images using semiconductor sensors has been extensively used as an X-ray imaging apparatus for medical image diagnosis and nondestructive inspection. Such an apparatus enables image acquisition in a way different from the conventional one using a photographic sensitive film, and an operator using the apparatus can immediately check acquisition of images, leading to improvement in work efficiency. The apparatus also covers a very wide dynamic range, resulting in the imaging that is not affected by a variable exposure amount of an X-ray.
As discussed in Japanese Patent No. 3848288, the progress of the reduction in size and weight of the apparatus enables practical use of the portable apparatus. The portable apparatus allows image acquisition of a patient at any attitude, and is readily used for X-ray imaging in a general hospital room and outside thereof.
Unfortunately, operators sometimes drop such a portable X-ray imaging apparatus due to carelessness while carrying it. The drop can be supposed to occur mostly from a height of about 0.5 to 1 m, from consideration of the height of a table and the height of a position the apparatus is carried at. Thus, the apparatus needs to have a sufficient mechanical strength.
Meanwhile, the apparatus generally cannot reduce the weight to less than 2.5 kg because it has electrical circuits configured to drive sensors incorporated therein. The weight causes a large impact energy on the apparatus when dropped. The X-ray imaging apparatus is sometimes placed under a subject for imaging. To reduce the uncomfortable physical contact of the apparatus given to the subject, a thin apparatus is common having a thickness of about 15 mm. Therefore, it is also difficult to increase rigidity and resistance to dropping of the X-ray imaging apparatus.
Japanese Patent Application Laid-Open No. 2006-006424 discusses an X-ray imaging apparatus provided with a buffer material on the sides thereof for impact absorption to secure an adequate strength. Further, Japanese Patent Application Laid-Open No. 2005-006806 discusses a protection frame for an X-ray imaging apparatus. The frame is used instead of the buffer material that increases the size of the apparatus, and is attached to the outside of a casing of the apparatus when it is carried.